<html>
  <body>
    <iframe src="visible_iframe.html"></iframe>
    <iframe width=0 height=0 src="zero_sized_iframe.html"></iframe>
    <iframe style="visibility:hidden;" src="invisible_iframe.html"></iframe>
    <p>This is a visible paragraph.</p>
    <p style="visibility:hidden;">This is an invisible paragraph.</p>
  </body>
</html>
